These catastrophes in first preseason games can’t be taken too seriously. What can, though, is the overall body of a summer’s work. And now that the Jets have started to play games, here’s what we know:

Neither Sanchez nor Geno Smith has shown any signs of command yet. If it continues this way, count on mucho trouble for Rex Ryan.

The fact that Smith practiced through the pain Sunday of the rolled ankle he suffered that same game is a good sign, as was his 7-of-10, four-touchdown performance in the red zone segment. But practice, of course, is practice, and Smith needs to show something against a real pass rush to ease the minds of offensive coordinator Marty Mornhinweg, Ryan, and GM John Idzik, the last of whom has placed his reputation as a talent evaluator ostensibly in the hands of a confidence-challenged incumbent and a rookie thrower an entire league passed by in the first round.

Still, if any good omen came from that 26-17 loss, it was that Smith came out to practice Sunday. He could have begged off, sat out drills as a precaution despite the clean scans. This still leaves the West Virginia product well short of heroic status, let’s be honest. But it showed he truly wants to be out there. It showed that, as cocky as he might be, he’s taking nothing for granted despite a growing chorus of chants urging Ryan to hand him the steering wheel within the season’s opening month.

“I felt it was important just to practice,” Smith said at the team’s Cortland training camp. “You can’t miss a day of practice. I pride myself on being out there at all times, and one little ankle injury wasn’t going to keep me from practicing and competing with my teammates.”

The sign that could sink the season is not Sanchez’ interception, or the near-miss he had when Kellen Winslow’s big hit knocked out another pick, but the mountain of penalties the Jets picked up. They were flagged 11 times for 85 yards. For other teams with stronger offenses, those numbers would simply be annoying. But the Jets are not going into the season with the firepower — regardless of whether Sanchez or Smith is doing the firing — to overcome lost real estate.

This is stacking up as a team that needs to play mistake-free. The preseason opener, like most around the league, was anything but.

This Jets squad is clearly not yet ready for prime-time. Whether they will be in three more games depends on whether they can clean up in time. That means eliminating the penalties that set the Jets back in their own end and, in Willie Colon‘s case, getting rid of the hold that endangered Sanchez’ only touchdown drive. It means Smith looking downfield for bigger yardage chunks. It means the running game generating more than 37 yards, and the defensive allowing less than 300.

There is certainly much work to be done. First preseason games are first preseason games, nothing more. The bigger omens come in their aftermath.

How Sanchez handles practice this week will tell much more about this team’s potential than that pick-six. So will the way Smith deals with his ankle sprain.

Ryan should look hard for the signs. Right now, he could use a positive one.

And not just because Ezekiel Ansah took one of his quarterbacks to the house Friday night.